Within the action string of the DroppableWidget, the action string of the ButtonWidget and the action string of the LinkCatcherWidget and the EventCatcherWidget, the modifier variable contains the modifier key(s) held during the drag-process. Possible key combinations are listed in the table below.
The variable contains a string that identifies the keys:
| Modifier Key | Variable Content |
| meta | meta |
| ctrl | ctrl |
| alt | alt |
| shift | shift |
| meta+shift | meta-shift |
| meta+ctrl | meta-ctrl |
| meta+alt | meta-alt |
| ctrl+shift | ctrl-shift |
| alt+shift | alt-shift |
| ctrl+alt | ctrl-alt |
| meta+ctrl+shift | meta-ctrl-shift |
| meta+ctrl+alt | meta-ctrl-alt |
| meta+alt+shift | meta-alt-shift |
| ctrl+alt+shift | ctrl-alt-shift |
| meta+ctrl+alt+shift | meta-ctrl-alt-shift |
| no modifier (normal click / drag) | normal |